Land management affects soil condition
As a large percentage of soils in Australia are a part of agricultural environments closely managed by farmers, the land management practices they choose can have a crucial impact on the condition of Australia’s soils. The condition of soil contributes significantly to the quality of ecosystem services a specific environment can provide. Improving management practices can reduce soil loss through wind and water erosion, and slow rates of acidification and soil carbon decline.
The figure below shows the dramatic difference land management decisions can make to ground cover and soil loss through wind erosion. Land management choices such as overgrazing can lead to decreased levels of ground cover (the layer of plant matter and other biological crusts holding the soil in place), contributing to wind erosion and increased dust levels. As the area of bare ground increases, there is greater risk of wind removing soil particles (including soil carbon and nutrients) as dust. The loss of these soil particles contributes to the decline of soil resource condition by reducing topsoil depth and removing lighter particles which can include nutrients and soil carbon, as well as reducing air and water quality as lost soil particles contaminate these systems. In contrast, management practices that contribute to the retention of ground cover will lessen the risk of wind erosion and water erosion removing soil particles. The result is a maintenance or improvement in overall resource condition.
Effect of land management decisions on ground cover and soil loss through wind erosion
Image modified after John Leys, Office of Environment and Heritage within NSW Department of Premier and Cabinet.
Caring for our Country Sustainable Practices National Priority Area
Recognising the important role farming practices play in managing soil condition and landscape conservation, Caring for our Country, the Australian Government’s natural resource management initiative, has provided funding for work to deliver projects addressing a range of sustainable practice targets. The targets relating to soil management are:
Improving land management practices
To increase by 42 000, farmers in identified priority regions that have improved their management to reduce the risk of soil acidification and soil loss through wind erosion, water erosion and improve carbon content of soils, or have adopted other improved soil management methods.
Increasing landscape scale conservation
To increase by 6700, farmers in priority regions adopting activities that contribute to the ongoing conservation and protection of biodiversity over four years.
Improving knowledge and skills of land managers
To increase by 42000, land managers and farmers over four years who have demonstrated an improvement in knowledge and skills in natural resource management.
These targets were provided under the 2009–10 business plan and will be addressed by projects across the 5 years of the Caring for our Country program.
Further information about the current Sustainable Farm Practices targets can be found on the Caring for our Country website.
Identification of areas where improving management practices will most benefit soil condition
Caring for our Country is supporting management practices that increase soil carbon storage, reduce the risk of soil acidification, and reduce the risk of wind and hillslope erosion. The relationships between some land management practices and soil condition are summarised in the table below.
National maps have been prepared by researchers and state agency experts that identify areas where improving land management practices is likely to have the most significant impact on reducing wind and water erosion and soil acidification risk and increasing soil carbon. These maps and corresponding reports are available for download below.
Managing soil pH (acidification) – preliminary estimates suggest that soil acidification problems may be affecting more than 1.4 million square kilometres of Australian soil (19% of the continent). High risk areas have been identified as those being managed fairly intensively for agriculture to which fertiliser is regularly applied, especially if these area have low resistance to pH change.
Map: Indicative locations where improving soil and land management practices to manage soil pH will provide the biggest benefits
Soil carbon – mapping identified about 202,625 square kilometres (2.7% of the continent) of Australia as having the best opportunities for increasing soil carbon. These areas are characterised by reasonable rainfall, have been cleared and managed for agriculture for some time (areas under long term agriculture, especially cropped areas often have substantially reduced levels of soil carbon) and are likely to have soils with a significant clay component. A further 838,850 square kilometres (11% of the continent) has been identified as having moderate potential to store carbon.
Map: Indicative locations where improving soil and land management practices to increase soil organic matter will provide the biggest benefits
Reducing soil loss through wind erosion – analysis of wind erosion information in 2009 indicated that around 1.29 million square kilometres (17%) of the continent may have been affected by widespread and moderate to severe wind erosion. Areas most likely to be affected are those where vegetation cover is low.
Map: Indicative locations where improving soil and land management practices to reduce soil loss from wind erosion will provide the biggest benefits
Reducing soil loss through water (hillslope or sheet and rill) erosion – The data currently available for a national assessment of the extent of hillslope erosion are very limited; the hillslope erosion map prepared for the Caring for our Country Business Plans provides a very general guide to the extent and severity of hillslope erosion. Streambank and gully erosion are also significant water erosion processes – although these occurrences are quite localised and no national assessments are currently available. These latter processes have not been included in the Sustainable Practices targets.
Map: Indicative locations where improving soil and land management practices to reduce soil loss from hillslope (sheet and rill) erosion will provide the biggest benefits.
|Practice||Type of agriculture||Increases carbon content||Reduces risk of wind erosion||Reduces risk of water erosion||Reduces risk of soil acidification (low pH)|
|No cultivation / tillage apart from actual sowing||Broadacre cropping||Indirectly||Y||Y|
|Stubble left intact||Broadacre cropping||Y||Y||Y|
|Reduce fallow#||Broadacre cropping||Y||Y||Y|
|Soil pH testing||Broadacre cropping|
|Lime or dolomite applied to reduce soil acidity||Broadacre cropping|
|Monitoring of ground cover||Beef cattle/ sheep meat grazing||Y||Y||Y|
|Use of ground cover management targets||Beef cattle/ sheep meat grazing||Y||Y||Y|
|Pasture phase in crop rotations||Broadacre cropping||Y||Indirectly||Indirectly|
|Increasing perennial pastures #||Beef cattle/ sheep meat grazing|
- Identification of areas within Australia for reducing soil loss by wind erosion Bureau of Rural Science report
- CSIRO report: Identification of areas in Australia where soil loss from hillslope erosion could be reduced
Monitoring land management practices
Caring for our Country aims to assist 42 000 farmers to improve practices across 70 million hectares of agricultural land by 2013. Trends in the adoption of practices that reduce the risk of soil acidification, soil loss through wind and water erosion and increase the carbon content of soils are being tracked biennially for over 33 000 farms across Australia using the Agricultural Resources Management Survey (ARMS) commissioned from the Australian Bureau of Statistics.
Practices monitored include cultivation, stubble management and soil pH management for cropping industries, soil pH management and inter row cover for horticulture industries, ground cover management and soil pH management in the dairy industry, and ground cover management in other grazing industries such as meat, cattle and sheep.
Emphasis is being placed on practices that affect the proportion of ground cover retained, because this factor has been shown to have a significant impact on the amount of soil redistributed or lost through wind and water erosion and on the biomass which could contribute to soil carbon storage.
Recent weather events have offered an opportunity to examine whether good ground cover would also protect soils under extreme conditions. The studies found that areas with low levels of ground cover prior to the floods were associated with higher levels of soil loss through water erosion.
The Queensland report ‘Ground Cover under Pressure: Case Study Analysis on the Effects of Ground Cover on Soil Loss During Extreme Flood Conditions in Queensland’ examined the impact of ground cover on soil loss in the Lockyer Valley (dominated by grazing) and the Condamine (dominated by cropping) catchments after the extreme flood events of January 2011. High levels of ground cover protected the Lockyer Valley from hillslope and rill erosion; but not from landslips which occurred over small areas of steeper slopes cleared of native vegetation. In the Condamine good vegetation cover and the retention of crop stubbles protected soils and soil conservation structures.
The Western Australian report ‘Report on the Gascoyne River catchment following the 2010/11 flood events’ identified that a tropical storm which delivered the highest rainfall on record over a 24 hour period, resulted in substantial soil loss and delivery of a major plume of sediment to the marine environment offshore of Carnarvon. Two subsequent floods also resulted in significant soil erosion. The Gascoyne River catchment has been in poor condition with reduced ground cover at least since the 1960s, and possibly the 1930s, due to recent poor seasons, coupled with the practice of continuous stocking through consecutive dry years, in excess of carrying capacity of the resource. Improving ground cover could be expected to reduce soil erosion losses.
- Gascoyne River catchment report PDF [2 MB, 105 pages]
- Gascoyne River catchment report DOCX [6 MB, 105 pages]
Caring for our Country’s Sustainable practice targets also include landscape scale conservation, which aims to achieve an additional 6 700 farmers adopting activities that contribute to the ongoing conservation and protection of biodiversity by 2013.
A set of fact sheets provide national and state/territory results for the broadacre cropping, horticulture, beef cattle/sheep and dairy industries. Similar reports now being prepared will show trends for NRM regions across the states/territories. Further information and copies of the fact sheets can be downloaded from the 'Reporting on trends in improved land management practices’ page.
Examples of Caring for our Country projects
The following projects are examples of the investment Caring for our Country is making to improve soil and land management through Sustainable Farm Practices. These projects address at least one of the three sustainable farm practices targets identified in the 2009–10 Caring for our Country business plan: improving land management practices, increasing landscape scale conservation, and improving the knowledge and skills of land managers.
Using these targets to guide activities, Caring for our Country projects such as these contribute to the understanding and adoption of better management practices that can improve management of wind and hillslope erosion, soil acidification and soil carbon.
Implementing the Grains Environmental Plan in partnership with Australia’s mixed system farmers:
Funding is being provided for the Grains Research and Development Corporation’s project to deliver key farming practices that positively impact on whole farm biomass production, wind and hill slope erosion, management of soil carbon and on–farm biodiversity, and to improve the knowledge and skills of farmers.
Improving soil acidity management of >1000 growers in southwest Western Australian agriculture:
Funding is being invested through the Western Australian Department of Agriculture and Food (DAFWA) to improve soil acidity management, knowledge and skills of agriculture growers in southwest Western Australia. A cost–shared soil sampling program will help identify locations where subsoil acidification may be occurring. Grower group workshops and acidity forums will be used to increase the awareness of soil acidity, address issues limiting practice adoption, provide acidity management skills to growers, and quantify the level of practice change. Supporting work, including sampling and analysis of local DAFWA liming demonstration sites, regional acidity modelling and Western Australian lime supplier audits, will enable farmers to confidently adopt soil acidity management practices to improve soil condition.
Promoting sustainable cropping practices for farmers in dryland agriculture:
The Conservation Agriculture Alliance of Australia and New Zealand (an alliance of 5 no–till grower groups) is receiving support to promote sustainable cropping practices for farmers in dryland agriculture. They will run a series of sustainable cropping farmer extension field days, case studies, video recordings and workshops looking at various no–till technology and controlled traffic farming practices covering over 23 regional catchments across the grains industry from Western Australia to Queensland.
Bega Cheese engaging 100% of their supplier base in New South Wales, Victoria and South Australia in implementation of Dairy Environmental Management System:
Bega Cheese is receiving support to implement their Bega Environmental Management System (BEMS) across their entire supplier base. BEMS is a tailored industry code of practice that provides a framework for assessing, recording and comparing management practices against industry standards, and identifying training needs. The process will facilitate the uptake and implementation of sustainable farm and land management practices and provide a mechanism for recording and monitoring improvement in management practices over time.